摘要 : New electroactive vinyl monomers, i.e., 3,6-dimethoxy-9-(4-vinylphenyl)-9H-carbazole and 3,6-dimethoxy-9-(3-vinylphenyl)-9H-carbazole were prepared by palladium catalyzed reactions of dimethoxy-9H-carbazole with 1-bromo-4-vinylben... 展开 New electroactive vinyl monomers, i.e., 3,6-dimethoxy-9-(4-vinylphenyl)-9H-carbazole and 3,6-dimethoxy-9-(3-vinylphenyl)-9H-carbazole were prepared by palladium catalyzed reactions of dimethoxy-9H-carbazole with 1-bromo-4-vinylbenzene or 1-bromo-3-vinylbenzene, respectively. Living radical polymerization of these monomers was carried out using 2-(dodecylthiocarbonothioylthio)-2-methylpropionic acid as a RAFT agent affording polymers with controlled molecular weight (up to M-n = 20,000) and low polydispersity (D<1.5). The obtained polymers exhibited delayed fluorescence caused by relaxation of excimer states. The lifetimes of long-lived components up to 2.6 mu s were obtained for the excimer emission by multi-exponential fitting of photoluminescence decay curves. The polymers were tested in solution-processed OLEDs. Green thermally-activated-delayed-fluorescence OLEDs with polymers as hole transporting materials demonstrated lower turn-on voltage and enhanced charge balance in emission layer compared to device fabricated using the commercial hole-transporting material. Additionally, the phosphorescent OLEDs based on red phosphor as dopant and the synthesized polymer as a host materials were fabricated and characterized. The best device showed external quantum efficiency of 10.6%. 收起